WO2014077066A1

WO2014077066A1 - Laser fusion-cutting method for plate glass

Info

Publication number: WO2014077066A1
Application number: PCT/JP2013/077760
Authority: WO
Inventors: 尚利稲山
Original assignee: 日本電気硝子株式会社
Priority date: 2012-11-13
Filing date: 2013-10-11
Publication date: 2014-05-22
Also published as: US20150307386A1; TWI583643B; CN104703932A; KR102073667B1; EP2921461B1; KR20150086181A; EP2921461A1; TW201422547A; US9725353B2; JP5975344B2; EP2921461A4; JP2014097906A; CN104703932B

Abstract

A laser fusion-cutting method for plate glass, that irradiates a laser (L) from a surface (S) side, along a planned cutting line (X) extending in the surface direction of plate glass (G), and cuts the plate glass (G). The method uses a configuration whereby a shaping gas (A3), sprayed so as to form a flow along the surface of at least either the front or rear surface (S, B) of the plate glass (G), passes through an irradiation section (C) for the laser (L).

Description

Laser cutting method for sheet glass

The present invention relates to a laser fusing method for a plate glass that cuts the plate glass by irradiating the plate glass with a laser along a planned cutting line and removing the molten glass melted by heating with the laser.

As is well known, in the manufacturing process of flat panel displays (FPD) such as liquid crystal displays, plasma displays, electroluminescence displays, organic EL displays, and flat glass products used for solar cells, large glass sheets are reduced to small glass sheets. Or trim the edge along the side of the glass sheet.

As one of the methods for cutting the plate glass as described above, a laser fusing method is known, and Patent Document 1 discloses an example thereof. This laser fusing method irradiates a laser along a planned cutting line extending in the surface direction of the workpiece to be cut, and removes the melted portion by heating with the laser by spraying an assist gas or the like. The workpiece is cut.

When this laser fusing method is applied to the cutting of sheet glass, the cut end of the sheet glass after cutting is formed on a smooth fired surface. Thereby, it is possible to give the cutting end portion an effect equal to or higher than that of the polishing mirror surface processing by a mechanical method.

Japanese Patent Laid-Open No. 8-141864

However, problems to be solved still remain in the laser fusing method having the excellent characteristics as described above. In the following description, among the front and back surfaces of the plate glass, the surface on which the laser is irradiated is referred to as “front surface”, and the opposite surface is referred to as “back surface”.

That is, in the cutting of the plate glass by the laser fusing method, it is very difficult to adjust the output of the laser irradiated on the plate glass, the injection pressure of the assist gas injected toward the laser irradiation portion, and the like. Due to this, there has been a problem that the cut end portion of the plate glass after cutting is easily formed into a defective shape.

More specifically, for example, when the output of the laser is high, the amount of molten glass melted by heating the laser becomes excessive. Thereby, as shown in FIG. 6, the thickness of the cut end Ga rounded by the action of the surface tension becomes larger than the thickness of other parts in the plate glass G, and the surface Gaa and the back surface Gab of the cut end Ga. Are formed in a protruding state (in the following description, the shape of this defective cut end is referred to as “dama”).

Also, this dama is formed in the same way when the beam mode of the laser irradiated on the plate glass inevitably deteriorates. Usually, the laser is focused by a lens or the like and irradiated so that its focal point is located at a predetermined position with respect to the surface of the plate glass. At this time, if the beam mode is inevitably deteriorated due to deformation of the optical element or the position of the focal point is extremely deviated from the predetermined position described above, the area and energy density of the position where the laser is irradiated are reduced. It will deviate from the proper range, and as a result, the amount of molten glass becomes excessive. As a result, as described above, lumps are formed as in the case where the output of the laser is high.

Furthermore, when the assist gas injection pressure is strong, the plate glass is unnecessarily strongly pressed by the gas pressure, so that the cut end Ga is lower than the other parts as shown in FIG. It is formed in a suspended state (in the following description, the shape of this defective cut end is referred to as sagging). In this case, this sagging is likely to be formed particularly when the thickness of the plate glass to be cut is thin.

In order to prevent the occurrence of this sagging, it is conceivable to remove the molten glass without using an assist gas. In this case, moisture and volatile components in the glass, or energy when the glass itself vaporizes and expands, becomes a driving force for removing the molten glass, thereby removing the molten glass. However, in this case, even when the laser is cut so that the focal point of the laser falls within the range of the predetermined position described above, the cut end portion of the plate glass after cutting has its front and back surfaces compared to other parts. It will be formed into a slightly protruding defective shape.

The present invention made in view of the above circumstances has a technical problem of forming a cut end portion of a plate glass after cutting into a good shape free from lumps and sagging in the cutting of the plate glass by a laser fusing method.

The method according to the present invention, which was created to solve the above-mentioned problems, is a method of laser cutting a plate glass by irradiating a laser from the surface side along a planned cutting line extending in the plane direction of the plate glass and cutting the plate glass. The shaping gas sprayed so as to form a flow along at least one of the front and back surfaces of the plate glass is characterized by passing through the laser irradiation section.

According to such a method, when the shaping gas is injected so as to form a flow along the surface of the plate glass, with the laser irradiation at the cut end portion of the plate glass that is sequentially formed in the laser irradiation unit, When the molten glass tries to be rounded by the action of surface tension, even if a bulge is formed on the surface side of the cut end, a force that pushes the bulge in the surface direction of the plate glass acts due to the pressure of the shaping gas. In addition, the surface side of the cut end is placed under a state where the atmospheric pressure is lower than that of the back surface side because the shaping gas passes through the surface side. Therefore, even if a bulge is formed on the back side of the cut end, a force acts to push the bulge from the back side having a high atmospheric pressure to the front side having a low atmospheric pressure. By the action of these two forces, both the front and back surfaces of the cut end are flattened and the formation of a bulge is prevented. As a result, it is possible to avoid a situation in which the shape of the cut end portion is poorly formed due to an excessive amount of molten glass such as formation of lumps. In addition, since the injected shaping gas forms a flow along the surface of the plate glass and passes through the laser irradiation part, the cutting end is strongly pressed from the front side to the back side by the pressure of the shaping gas. Therefore, the formation of sagging can be avoided. Furthermore, if the assist gas is injected toward the laser irradiation part, even if a sag is formed at the cut end due to the pressure of the assist gas, the above-described protrusion is also applied to the sag from the back side. The force pushing into the surface side acts. Therefore, even in this case, the formation of sagging can be avoided accurately. From the above, according to the method according to the present invention, in cutting the plate glass by the laser fusing method, the cut end portion of the cut plate glass can be formed into a good shape free from lumps and sagging. In addition, when shaping gas is injected so that the flow along the back surface of plate glass may be injected, the force which pushes out the protrusion which is going to be formed in the back surface side of a cutting | disconnection edge part acts on the surface direction of plate glass. In addition, since the pressure on the back side is lower than that on the front side, the protrusions that are to be formed on the front side of the cut end are pushed from the high pressure side to the low pressure side. Will be. From these things, the same effect as the case where the shaping gas is injected so as to form the flow along the surface of the plate glass as described above can be obtained also in this case. Furthermore, the same effect can be obtained when the shaping gas is injected so as to form a flow along both the front surface and the back surface of the plate glass. In this case, among the front and back surfaces of the plate glass, it is preferable that the shaping gas injected to the back side is injected so that the flow velocity passing through the cutting end is slower than the shaping gas injected to the front side. In this way, since the pressure on the back surface side is maintained higher than that on the front surface side, there is a risk that the action of pushing the ledge to be formed on the back surface of the cut end portion from the back surface side to the front surface side may be lost. Can be eliminated.

In the above method, it is preferable that the shaping gas forms only a flow along the surface of the plate glass.

Generally, when a plate glass is supported by a processing table, the back surface of the plate glass is in contact with the processing table. Therefore, there will be a processing table in the vicinity of the back surface of the plate glass in the laser irradiation section, and when the shaping gas forms a flow along the back surface of the plate glass, the flow of the shaping gas is disturbed by this processing table, and the cutting end The effect of improving the shape of the part may be reduced. For this reason, it is more preferable that the shaping gas forms only a flow along the surface of the plate glass.

In the above method, it is preferable that the shaping gas injection direction and the front and back surfaces of the plate glass are parallel to each other.

In this way, it is possible to prevent the occurrence of a situation in which the flow velocity of the injected shaping gas is decelerated due to the collision between the shaping gas and the plate glass, and the flow velocity of the shaping gas passing through the cutting end is as much as possible. Can be increased. Moreover, the higher the flow velocity of the shaping gas passing through the cutting end, the greater the pressure of the shaping gas acting on the ledge that is to be formed on the front surface side, and the atmospheric pressure difference between the front surface side and the back surface side. Therefore, for example, when the shaping gas forms a flow along the surface of the front and back surfaces of the plate glass, it will be formed on the back surface side with the action of pushing out the protrusion to be formed on the front surface side in the surface direction of the plate glass. The action of pushing the bulge from the back side to the front side can be expressed more favorably.

In the above method, it is preferable that a gas injection member having an injection port for injecting the shaping gas is provided, and the injection port has a wide shape in a direction parallel to the front and back surfaces of the plate glass.

In this way, the injected shaping gas spreads over a wide range of the cut end portion following the shape of the injection port. For this reason, it becomes possible to prevent the formation of the protrusion at the cut end more stably.

In the above method, it is preferable that the thickness of the plate glass is 500 μm or less.

That is, in the conventional method, if the thickness of the plate glass is 500 μm or less, it was difficult to suppress the occurrence of sag particularly at the cut end, but according to the method of the present invention, such a plate thickness Even a thin plate glass can sufficiently suppress the occurrence of sagging.

In the above method, it is preferable that the assist gas is injected from the direction inclined with respect to the surface of the plate glass toward the laser irradiation portion.

In this way, the molten glass melted by the laser heating can be scattered and removed by the pressure of the assist gas, so that the molten glass can be removed more quickly and smoothly. In addition, since the assist gas is sprayed to the irradiation part from the direction inclined with respect to the surface of the plate glass, the cut end of the plate glass is strongly pressed from the front side to the back side by the pressure of the assist gas. Is avoided. For this reason, it is possible to prevent the occurrence of sagging at the cut end portion in combination with the above-described action by the shaping gas injection.

In the above method, it is preferable that the laser is condensed and irradiated with a lens, and gas is injected along the irradiation direction of the laser.

In this way, it is possible to prevent as much as possible the occurrence of the situation where the scattered dross adheres to the lens by the pressure of the gas injected along the laser irradiation direction.

In the above method, the cutting glass cutting direction is crossed with the direction in which the shaping gas passes through the laser irradiation part, and the two pieces of plate glass after cutting are positioned on the injection side of the shaping gas. It is preferable that the plate glass to be used is a product and the plate glass located on the injection destination side is a non-product.

That is, when comparing the plate glass located on the injection source side of the shaping gas and the plate glass located on the injection destination side with respect to the magnitude of the effect of preventing the formation of the protrusion at the cut end, the plate glass located on the injection source side You can get a big effect. In addition, since the dross generated when cutting the plate glass is likely to be scattered to the shaping gas injection destination side, the dross is less likely to adhere to the cut end portion of the plate glass located on the injection source side. Therefore, the quality of a product can be improved if the plate glass located in the shaping gas injection side is used as a product among both the plate glasses after cutting.

As described above, according to the present invention, the shaping gas injected so as to form a flow along at least one surface of the front and back surfaces of the plate glass passes through the laser irradiation portion, and thus is based on the laser fusing method. In cutting the plate glass, the cut end portion of the cut plate glass can be formed into a good shape free from lumps and sagging.

It is a vertical front view which shows the laser fusing apparatus used for the laser fusing method which concerns on embodiment of this invention. It is a partial cross section top view which shows the laser fusing apparatus used for the laser fusing method which concerns on embodiment of this invention. It is side surface sectional drawing which shows the effect | action of the laser fusing method which concerns on embodiment of this invention. It is side surface sectional drawing which shows the effect | action of the laser fusing method which concerns on embodiment of this invention. It is side surface sectional drawing which shows the effect | action of the laser fusing method which concerns on embodiment of this invention. It is side surface sectional drawing which shows the effect | action of the laser fusing method which concerns on embodiment of this invention. It is side surface sectional drawing which shows the laser fusing method which concerns on other embodiment of this invention. It is side surface sectional drawing which shows the laser fusing method which concerns on other embodiment of this invention. It is side surface sectional drawing which shows the shape of the cut end part formed in defect. It is side surface sectional drawing which shows the shape of the cut end part formed in defect.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In this embodiment, a horizontally placed plate glass is cut by a laser fusing method along a planned cutting line, and the plate glass is divided into a product part to be a product and a non-product part to be a non-product (waste). The case of dividing will be described as an example.

FIGS. 1 and 2 are a longitudinal sectional front view and a partial cross-sectional plan view showing a laser fusing device used in a sheet glass laser fusing method according to an embodiment of the present invention, respectively. As shown in these drawings, the laser fusing device 1 includes a processing table 5 on which a plate glass G is placed, a laser irradiator 2 that irradiates a laser L toward the surface S of the plate glass G, and heating of the laser L. The main elements are an assist gas injection nozzle 3 that injects an assist gas A2 that scatters molten glass M, and a shaping gas injection nozzle 4 as a gas injection member that injects shaping gas A3 along the surface S of the glass sheet G. Configured as

The laser irradiator 2 is installed at a fixed position, and is composed of a cylindrical base end portion and a mortar-shaped tip end portion. A lens 6 that collects a laser beam L emitted from a laser oscillator (not shown) and irradiates the surface S of the glass sheet G is attached to the inner peripheral wall of the base end portion. In addition, a gas introduction pipe 2a for introducing the gas A1 injected along the irradiation direction of the laser L into the laser irradiator 2 is connected to the tip, and the laser L and the gas A1 are irradiated and injected. A circular illumination outlet 2b for this purpose is formed.

The assist gas injection nozzle 3 is installed at a fixed position in the same manner as the laser irradiator 2 and is installed in a posture inclined with respect to the surface S of the plate glass G. The shape is formed in a cylindrical shape, and assist gas A2 compressed by a gas compression device (for example, an air compressor) (not shown) passes through the inside and is injected toward the irradiation part C of the laser L. It is comprised so that.

The shaping gas injection nozzle 4 is installed at a fixed position on the surface S side in the same manner as the laser irradiator 2 and the assist gas injection nozzle 3, and is in a posture parallel to the surface S of the plate glass G and in the plane direction of the plate glass G. It is installed in the direction orthogonal to the planned cutting line X extending in the direction. The injection port 4a formed in the cross section and the front-end | tip is formed in the substantially rectangular shape, and the injection port 4a is wide in the direction along the cutting projected line X. As shown in FIG. And the shaping gas A3 compressed with the gas compression apparatus abbreviate | omitted illustration passes through the inside, and becomes a structure injected in parallel with the surface S of the plate glass G from the injection port 4a. Moreover, this shaping gas A3 is injected toward the side used as the non-product part G2 from the side used as the product part G1 among the both glass plates G after a cutting | disconnection.

A pair of processing tables 5 are installed in parallel across the planned cutting line X. Moreover, both the process bases 5 become a structure which can move synchronizing with the T direction (direction parallel to the cutting projected line X) shown in FIG. 2 in the state in which the plate glass G was mounted.

From the above, in the laser fusing device 1, the laser irradiator 2 continuously lasers the surface S of the plate glass along the planned cutting line X as the processing table 5 on which the plate glass G is placed moves in the T direction. L is irradiated. Then, the molten glass M melted by the irradiation part C of the laser L is removed by blowing away and scattering the assist gas A2 sprayed from the assist gas spray nozzle 3. After that, the shaping gas A3 injected from the shaping gas injection nozzle 4 passes along the surface S of the plate glass G and the cutting progress direction of the cut end Ga formed sequentially on the plate glass G along with the removal of the molten glass M. It is comprised so that it may pass orthogonally. Further, the dross scattered when the molten glass M is removed is prevented from adhering to the lens 6 by the pressure of the gas A1 ejected from the laser irradiator 2.

Here, the injection pressures of the gas A1, the assist gas A2, and the shaping gas A3 are as follows: the gas A1: 0.00 to 0.02 MPa, the assist gas A2: 0.00 to 0.25 MPa, and the shaping gas A3: 0.01. It is preferable that the pressure is 1.0 MPa. Further, the separation distance between the injection port 4a formed in the shaping gas injection nozzle 4 and the planned cutting line X is preferably 1 to 30 mm, more preferably 1 to 10 mm. Furthermore, the angle formed by the assist gas A2 injection direction and the surface S of the glass sheet G is preferably 25 to 60 °.

Hereinafter, the operation of the laser glass cutting method using the above laser cutting device 1 will be described with reference to the accompanying drawings. In addition, in drawing for explaining this effect | action, illustration of the plate glass of the side used as a non-product part is abbreviate | omitted among the both plate glasses after a cutting | disconnection.

When the molten glass M melted at the irradiation portion C of the laser L is blown off and removed with the pressure of the assist gas A2, the cut end portions Ga are sequentially formed on the plate glass G accordingly. At this time, when the output of the laser L is high, or when the beam mode of the laser L is inevitably deteriorated, the amount of the molten glass M melted is excessive.

For this reason, as shown by a two-dot chain line in FIG. 3a, the molten glass M tends to be rounded by the action of surface tension, and the surface Gaa and the back surface Gab of the cut end portion Ga are formed to protrude. However, as shown in FIG. 3B, a force F that pushes the protrusion in the surface direction of the plate glass G (product part G1) acts on the protrusion to be formed on the surface Gaa by the pressure of the shaping gas A3.

In addition, the surface Gaa side of the cut end Ga is placed under a state where the atmospheric pressure is lower than that of the back Gab side because the shaping gas A3 passes through the surface Gaa side. Therefore, as shown in FIG. 3c, a force P acts to push the protrusion to be formed on the back surface Gab from the back surface Gab side having a high atmospheric pressure to the surface Gaa side having a low atmospheric pressure. By these two forces F and P, both the front and back surfaces Gaa and Gab of the cut end Ga are flattened, and as shown in FIG.

Moreover, when these effects are manifested, the shaping gas A3 forms a flow along the surface S of the glass sheet G, so that a situation where the flow of the shaping gas A3 is disturbed by the processing table 5 is avoided. Is possible. Further, since the flow rate of the injected shaping gas A3 is decelerated due to the collision between the shaping gas A3 and the plate glass G due to the injection in parallel with the surface S of the plate glass G, the occurrence of a situation where possible. Can be prevented. In addition, the higher the flow velocity of the shaping gas A3 that passes through the cutting end Ga, the higher the pressure of the shaping gas A3 that acts on the ledge to be formed on the surface Gaa side, and the pressure difference between the surface Gaa side and the back surface Gab side. Becomes larger. For this reason, the action of pushing the protrusion to be formed on the surface Gaa of the cut end Ga in the surface direction and the action of pushing the protrusion to be formed on the back surface Gab from the back surface Gab side to the surface Gaa side are good. Expressed in

Furthermore, since the injection port 4a formed in the shaping gas injection nozzle 4 is wide in the direction along the surface S of the glass sheet G, the injected shaping gas A3 is cut following the shape of the injection port 4a. It spreads over a wide range of the end Ga. For this reason, it becomes possible to prevent the formation of the protrusion at the cut end Ga more stably.

Further, since the assist gas A2 is sprayed toward the irradiation part C of the laser L, the molten glass M melted in the irradiation part C can be scattered and removed by the pressure of the assist gas A2, Removal of the molten glass M can be performed more quickly and smoothly.

As a result, it can be avoided that the shape of the cut end Ga, such as formation of lumps, is defective. In addition, since the injected shaping gas A3 passes through the cutting end Ga along the surface S of the glass sheet G, the cutting end Ga is strongly moved from the surface Gaa side to the back surface Gab side by the shaping gas A3. It is also prevented from being pressed. For this reason, no sagging is formed in the cut end Ga by the shaping gas A3.

Furthermore, the risk of sagging at the cut end Ga due to the pressure of the assist gas A2 is also accurately eliminated as described below. That is, even if a sag is formed at the cut end Ga by the pressure of the assist gas A2, the force P that pushes the bulge already described from the back surface Gab side to the front surface Gaa side acts on this sag. Therefore, the formation of sagging is avoided accurately.

Also, dross generated when cutting the glass sheet G is likely to be scattered toward the injection destination side of the shaping gas A3. Therefore, it becomes difficult for dross to adhere to the cut end portion Ga of the product portion G1 located on the injection source side of the shaping gas A3 in the plate glass G after cutting, and the product portion G1 can be made of high quality. .

In addition, according to the laser fusing method according to the present embodiment, a thin glass having a thickness of 500 μm or less, which has been difficult to suppress the occurrence of sagging at the cut end Ga, is particularly an object to be cut. Even if it exists, it is possible to cut | disconnect, without forming sagging in the cutting | disconnection edge part Ga. In addition, as thickness of the plate glass G used as the object of a cutting | disconnection, it is more preferable to set it as 300 micrometers or less, Most preferably, it is 200 micrometers or less.

Here, the laser fusing method for plate glass according to the present invention is not limited to the configuration described in the above embodiment. For example, in the above-described embodiment, the cutting progress direction and the direction in which the shaping gas passes through the laser irradiation unit are orthogonal to each other. However, these may only intersect without being orthogonal. However, they may be parallel. That is, the shaping gas may be injected in any direction as long as the injected shaping gas passes through the laser irradiation portion along the surface of the plate glass. Further, the shaping gas is not necessarily injected in parallel with the surface of the plate glass, and may be injected from a direction inclined with respect to the surface S of the plate glass G as shown in FIG. In this case, the angle α formed by the injection direction of the shaping gas and the surface S of the glass sheet G is preferably 0 to 25 °, more preferably 0 to 15 °, and most preferably 0. ~ 5 °. In this case, when the point where the center line 4b of the shaping gas injection nozzle 4 and the surface S of the glass sheet G intersect is defined as the intersection point 4c, the distance between the intersection point 4c and the irradiation part C of the laser L is 1 to 30 mm. More preferably, it is 2 to 10 mm, and most preferably 2 to 5 mm.

Further, the shaping gas may be injected along both the front and back surfaces of the plate glass. That is, in the above embodiment, the shaping gas is injected so that only the surface side of the laser irradiation portion passes along the surface of the plate glass, but as shown in FIG. The shaping gas A3 may be injected not only on the front surface Gaa side but also on the back surface Gab side. In this case, it is preferable that the shaping gas A3 injected to the back surface Gab side is injected so that the flow velocity passing through the cutting end Ga is slower than the shaping gas A3 injected to the front surface Gaa side. In this case, since the pressure on the back surface Gab side is maintained higher than that on the front surface Gaa side, there is a risk that the action of pushing the protrusion to be formed on the back surface Gab from the back surface Gab side to the front surface Gaa side may be lost. Can be eliminated. Even when the shaping gas A3 is injected so as to pass through the back surface Gab, the shaping gas A3 may be injected from a direction inclined with respect to the back surface B of the plate glass G. Moreover, you may inject so that shaping gas may form only the flow along the back surface of plate glass, and also in this case, the same effect as the case where the flow along the surface is formed can be acquired.

In addition, in the above embodiment, the molten glass is scattered and removed by spraying the assist gas. However, the molten glass can be removed without spraying the assist gas. In this case, moisture and volatile components in the glass, or energy when the glass itself vaporizes and expands, becomes a driving force for removing the molten glass, whereby the molten glass is scattered and removed.

In addition, the shape of the injection port formed in the shaping gas injection nozzle is rectangular in the above embodiment, but is not limited to this, and may be formed in any shape. However, it is preferable that the shaping gas injected from the injection port has a shape that spreads over a wide range of the cutting end, such as an ellipse having a major axis in a direction parallel to the surface of the plate glass. Shape is assumed.

Furthermore, in said embodiment, although it has become the aspect which melts | melts the plate glass mounted on the processing stand, For example, as an aspect which melts continuously the strip | belt-shaped glass ribbon shape | molded by the overflow method or the float method. It is good to use a glass roll obtained by winding a glass ribbon into a roll, and roll-to-roll (after unwinding the glass ribbon from the glass roll and applying the predetermined processing, the processed glass ribbon is wound again as a glass roll. It is good also as an aspect which carries out fusing by the aspect to take.

As an example of the present invention, cutting of a plate glass by a laser fusing method was attempted under the following two conditions, and the quality of the shape of the cut end of the cut plate glass was investigated.

The following table shows the cutting conditions when the plate glass is cut. In the table below, what is in parentheses in the item of laser medium indicates the wavelength of the laser. Moreover, the conveyance speed of plate glass represents the speed | rate which plate glass moves relatively with respect to the laser irradiator fixed to the fixed point, the injection nozzle of assist gas, and the injection nozzle of shaping gas. Furthermore, the injection angle of the assist gas and the injection angle of the shaping gas represent these inclination angles with respect to the surface of the plate glass. In addition, in the table below, the item “None” indicates that the assist gas or the shaping gas was not injected.

After cutting the plate glass under the conditions shown in the above table, when the quality of the cut end portion in the plate glass after cutting was investigated, in both Examples 1 and 2, the cut end portion was substantially semicircular. It was confirmed that it was formed in a good shape. Here, under these conditions, the cut end was formed in a good shape because the injected shaping gas passed through the cut end (laser irradiation part) formed sequentially on the plate glass. It is assumed that it was possible to prevent the protrusions from being formed on the front and back surfaces of the cut end.

DESCRIPTION OF SYMBOLS 1 Laser cutting apparatus 2 Laser irradiator 2a Gas introduction pipe 2b Illumination injection port 3 Assist gas injection nozzle 4 Shaped gas injection nozzle

4a Injection port

4b Center line 4c Intersection 5 Work table 6 Lens L Laser A1 Gas A2 Assist gas A3 Shaped gas G Sheet glass S Surface of sheet glass B Back surface of sheet glass Ga Cutting edge of sheet glass Gaa Surface of cutting edge Gab Back surface of cutting edge G1 Product part G2 Non-product part M Molten glass X Cutting line T Cutting direction of movement F Cutting edge Force acting on the part P Force acting on the cutting edge

Claims

A laser fusing method of plate glass that irradiates a laser from the surface side along a planned cutting line extending in the surface direction of the plate glass, and cuts the plate glass,
A laser fusing method for plate glass, wherein shaping gas injected so as to form a flow along at least one of the front and back surfaces of the plate glass passes through the laser irradiation section.
The method of laser fusing a plate glass according to claim 1, wherein the shaping gas forms only a flow along the surface of the plate glass.
3. The method of laser cutting a plate glass according to claim 1 or 2, wherein the shaping gas injection direction and the front and back surfaces of the plate glass are parallel to each other.
The gas injection member having an injection port for injecting the shaping gas is provided, and the injection port has a wide shape in a direction parallel to the front and back surfaces of the plate glass. The method for laser fusing of the described sheet glass.
5. The method of laser cutting a plate glass according to claim 1, wherein the thickness of the plate glass is 500 μm or less.
6. The method for laser cutting a plate glass according to claim 1, wherein the assist gas is sprayed from a direction inclined with respect to the surface of the plate glass toward the laser irradiation portion.
The method of laser cutting a plate glass according to any one of claims 1 to 6, wherein the laser is condensed by a lens and irradiated, and gas is jetted along the irradiation direction of the laser.
The direction of cutting of the plate glass intersects the direction in which the shaping gas passes through the laser irradiation part, and the plate glass located on the injection source side of the shaping gas among the two plate glasses after cutting is used as a product. The method of laser fusing a sheet glass according to any one of claims 1 to 7, wherein the sheet glass located on the ejection side is a non-product.